This paper presents the measured impedance by a distance relay with positive sequence voltage memory in the presence of thyristor controlled series compensator (TCSC), one of the series connected FACTS devices, on a transmission line. The measured impedance by distance relay is affected by the system structural conditions, pre-fault loading, and the ground fault resistance, as well as the presence of TCSC. In addition to compensation degree, TCSC installation location also affects the measured impedance. The variation of the ideal tripping characteristic due to compensation degree, and TCSC installation location would be investigated.